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SAproxy was under SpamAssassin SourceForge project as an open source project for a time .(How can be an open source project be open only for a time?!).
SAproxy Pro is (was) a commercial derivative of SAproxy. According to some people point of view (please respect freedom of speach) the company must release the source code and has not done it (interested in details, see http://wiki.apache.org/spamassassin/SaProxyStatus?action=diff&date=1098436420)
SAproxy major Major and minor versions and realeases (based on http://cvs.sourceforge.net/viewcvs.py/spamassassin/pop3/ )
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